Carlsbad Caverns National Park, New Mexico

Carlsbad Caverns National Park is in the Guadalupe Mountains in southeastern New Mexico. Carlsbad Caverns includes a large cave chamber, the Big Room, a natural limestone chamber which is almost 4,000 feet (1.2km) long, 625 feet (190 m) wide, and 350 feet (107 m) high at the highest point. It is the third largest chamber in North America and the seventh largest in the world.